The Outfit

All ranked matches count toward these achievements.

I became bored one day and dedicated some time to the math behind the various methods proposed to finish as quickly as possible.

For all of the following data, these are the conditions:
a) I was double boxing so it was all business by readying up immediately, not watching YouTube between matches or talking to a boosting partner, etc -- your mileage may vary;
b) I used a stopwatch to record all time, and did not rely on what the game told me;
c) all time recorded is lapse between victory screens, since the loading and lobbying in between counts!

Be aware at the outset that the other solutions only detail how to win matches for this achievement without any consideration for the partner achievement Prisoner of War for losing 200 matches. Their suggestions are all well and good, but the problem is that, without considering both achievements at once, you're adding extra time to your boost for no good reason. I'll get into the specifics as the solution continues.

There are three total methods for burning through the boost on this game.

Quitting out
What it says on the tin -- the designated loser simply quits the match from the pause menu and is returned to the main menu. The average time for a quit-out is 29.301 seconds and clocks in as the fastest of all proposed methods by a long shot, but carries the distinct disadvantage of not counting losses for the person quitting out. It makes a great secondary method in the interest of time once the quitter has his Prisoner of War achievement, but they will ultimately need to do one of the following two methods for that achievement.

Suiciding
Set the match to 50 Command points, and Respawn Delay to None. All other settings do not matter. As soon as the players spawn, the loser will repeat the pattern to run down their respawns until the match ends. This method takes an average of 54.609 seconds per match to accomplish but is the most involved, taking 30+ solid seconds of button mashing to end the game.

Running
Set the Starting Resources to 200. All other settings do not matter. Use the Blood Valley or Urban Combat map because these are the only two small maps with no default AI spawns, and it's a crap shoot on maps like Estate Assault because you risk an RPG or grenade obliterating your attempt at being speedy. Spawn the cheapest car/jeep available (character does not matter), then drive to the other flag and simply wait for the match to end for an average of 57.856 seconds each time.

So how does this pan out?
Over an entirety of 500 matches, you're looking at the following for a single person using the average times:

Quitting out: 4.07 hours
Suiciding: 7.58 hours
Running: 8.04 hours

It may seem pretty obvious from these stats which of these you want to do, but do not forget that quitting out does not count a loss for the quitter. You are therefore required to finish 200 matches either by suiciding or running.

200 matches of suiciding: 3.03 hours
200 matches of running: 3.21 hours
300 matches of quit outs: 2.44 hours

Career boost quit outs+suiciding: 5.47 hours
Career boost quit outs+running: 5.65 hours

The difference between suiciding and running a jeep to the enemy flag has a total difference of 10.8 minutes over the entirety of your boost, which makes for an almost insignificant difference. I personally went for driving the jeep because it's much less difficult than button-spamming for suiciding, and it's also slightly more entertaining to go for a leisurely drive instead of watching your group of soldiers collapse over and over.

But wait, there's more
Unless you're fortunate enough to have a dual box setup, you must double all of the provided projections. Let's take a look at how this works:

Player A runs 200 matches.
Player A has 200 wins, 0 losses.
Player B has 0 wins, 200 losses. (+Prisoner of War)

Player A quits out 300 matches.
Player A has 200 wins, 0 losses.
Player B has 300 wins, 200 losses.

This concludes Player A's contributions for a total of 5.65 hours. This must now be doubled:

Player B runs 200 matches.
Player A has 200 wins, 200 losses. (+Prisoner of War)
Player B has 500 wins, 200 losses. (+Victories Keep Piling Up)

Player B quits out 300 matches.
Player A has 500 wins, 200 losses. (+Victories Keep Piling Up)
Player B has 500 wins, 200 losses.

This scenario takes a total of 11.3 hours.

The easiest way to get this achievement is by boosting with a friend. Take it in turns to quit out of the match in lots of 10 games at a time, or something that can be agreed upon, and quit out as soon as the game starts.

This counts for victories, but not defeats.

I just did this last night, and all I can say is it's very time consuming. As long as the other player quits, you get a win, regardless what the leaderboards say.

This can be done in quick or custom match, HOWEVER it must be ranked. I did it on quick match to get a rough estimate (via the leaderboards) of how close I was.

In short, the VICTORY screen must appear 500 times and the achievement is yours... is a long haul though.

Interestingly enough, when you do the "quit out" method, for some reason your losses on the leaderboards go up. (When I unlocked this I had 687 total games, 245 wins and 442 losses, but we did some custom games too) Since you dont get losses for quitting out, I suggest you get the "200 losses" achievement first, then subtract 200 from your total games played. That will give a rough estimate of how close you are to the 500.

Or you could just do it on custom match, that way you won't be bothered by the 5 people that still play this game online.

Thanks xOBKx! This method works.

But if you want to cut the time in half to unlock this terrible achievement, it is possible to boost this game using double-box boosting. Here's what you'll need:

-2 Xbox 360
-2 Xbox Live Gold accounts (or a free gold weekend)
-2 copies of the game (you can easily find 1 for 5$)
-1 Hori turbo controller

With your main account (the one you want to unlock the achievement with), start the game and go into Multiplayer - Xbox Live - Ranked Game - Custom Game and stay there. Using your turbo controller, keep pressing the A button.

Now with your second account, go to Multiplayer - Xbox Live - Ranked Game - Custom Game and create a new game. Your main account will join and ready up. Start the game, wait for the loading screen to pass, and when you see the character selection screen, press Start and Quit. You don't have to advance into the character selection screen and spawn location at all. Just quit.

Now repeat the last step ... 499 times...

I was averaging 2 games a minute with this method, hence 120 games/hour, and 500 in 4 hr 10min. However, it took >5 hours for the achievement to unlock. I don't know why, I think the game is a bit glitched, so don't panic if you get to 500 and the achievement doesn't unlock.

Good luck!

P.S. You can also unlock all online achievements with this setup.

The easiest way to get this achievement is by boosting it.

Now it says 500 but it took me 16hours non stop with. a mate.

Now The Leader Borad dont take any notice of it, as it sead i had only won 34 games. ( For Some Resson it wont update wins/loses)

now i did well over 500 wins for it to unlock round 600/700.

and have seen ppl saying it has taken them up 900 to get the achievement witch i can belive it.

its a hell of a grind. find someone that wont mess about.

Take it in turns to quit out of the match in lots of 50 or 100 games at a time, and quit out as soon as the game starts.

This counts for victories, but not loses.

But when i did it i got 600/700 wins a row. and my mate was going for loses , all tho it wont count for loses what we did was if it was a short map like blood vaile ther are 2 other maps i forgot the name of that we did as well. i would take his base as it takes 10/20secs more.

he got his 200loses about 30/40 games before i pop my 500.

all so take note the 200 loses is all so bugged taken my mate 426 loses before it unlocked

Just a comment/tip for boosters - for two players with no MP play at all, it took 8 x 3 hour sessions to knock out all the MP achievements and you'll probably unlock this last of all (frankly you would have done something bizzare if this isn't your last one).

The walkthrough guide isn't quite explicit enough and you do need to suicide out for losses, but the match quit method is fine after that for the remaining victories. However xbox live (or the game itself) is very flakey.. you cannot go for speed, you will just crash and hang the game regularly during the quit out process (specifically, when trying to match up again). I suspect that the previous games are not removing themselves from either the game or XBL properly and thus a little bit of time is needed to flush it all through. Anyway, let all the screens display naturally and always count a second after every menu press - quit the game after the last pop-up menu, about 6 or so seconds into the game. You'll get a genuine 38 or 39 per hour each - and we even achieved a run of 43 victories each before the first crash on the final session, in fact there were only two crashes and one game reset in a session of 110 matches or so. That was excellent compared to the previous ones! It is best to be patient than to race - Good luck out there!